A Conference on High Voltage Electron Microscopy in Biomedical Research is proposed, to be held on the campus of the University of Pennsylvania on November 12 and 13, 1980. The major goals of the conference will be: 1) to summarize some of the important areas where significant advances in the understanding of biological structure and function have been made through use of HVEM, 2) to discuss what aspects of these studies and the associated specimen preparation techniques used have been important or essential in the success of these projects, 3) to discuss what specific capabilities of the HVEM instrument itself have made these successes possible and what future developments in HVEM instrumentation might further enhance these capabilities, 4) to predict what areas of biological research can be expected to profit most from HVEM in the near future, 5) to compare alternative methods, such as STEM, for examination of thick biological preparations to HVEM, and 6) to evaluate the need for additional facilities for biomedical HVEM in this country. Approximately 8 international leaders in the field will be invited to give major lectures. Other attendees may be asked to give shorter presentations or to prepare posters or other forms of demonstration of their work. The results and conclusions of the conference will be summarized in a report to be preparecd by the Conference Director in consultation with the invited speakers.